Objective This paper examines trends in the neighbourhood food store environment (defined by the number and geographic density of food stores of each type in a neighbourhood), and in food consumption behaviour and overweight risk of 5779 men and women.

Design The study used data gathered by the Stanford Heart Disease Prevention Program in four cross-sectional surveys conducted from 1981 to 1990.

Setting Four mid-sized cities in agricultural regions of California.

Subjects In total, 3154 women and 2625 men, aged 25–74 years.

Results From 1981 to 1990, there were large increases in the number and density of neighbourhood stores selling sweets, pizza stores, small grocery stores and fast-food restaurants. During this period, the percentage of women and men who adopted healthy food behaviours increased but so did the percentage who adopted less healthy food behaviours. The percentage who were obese increased by 28% in women and 24% in men.

Conclusion Findings point to increases in neighbourhood food stores that generally offer mostly unhealthy foods, and also to the importance of examining other food pattern changes that may have a substantial impact on obesity, such as large increases in portion sizes during the 1980s.